Degradation products of mangiferin by gamma irradiation with inhibitory effects on NO production.

The xanthone glucoside mangiferin (1) was converted by γ-irradiation into three new compounds, mangiferdiol (2), mangiferinol (3), and isomangiferinol (4). The new compound 2 containing two hydroxymethyl groups instead of a ketone moiety exhibited significantly improved inhibitory activity against nitric oxide production in lipopolysaccharide-stimulated RAW264.7 cells with IC50 value 47.1 ± 1.7 μM, compared to the mother mangiferin.